Positioning mechanism.



Patented June 15, 1915.

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Patented June 15, 1915.

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POSITIONING MECHANISM.

APPLICATION FILED SEPT. 26. m4.

Patented Jl me 15, 1915.

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To ail whom z'tymay concern: I Be it known that IS, WIIMIAM SHnRMnN Bsowm, a citizen of the United States, reslding at Knoxville, in the county of Knox and State of Tennessee, have invented a new and useful Improvement in Position-ing Mechanisrn, of which the following is a specification, reference being had to the accompanying drawing. Y

My improvement relates particularly to mechanism for at the will olf the operator placing or positioning :a mechanical memher into any chosen position within the range of the movement of said member and there holding said member until it is desired to bring it into another chosen position within said range of movement.

The object of the improvement is to provide such a mechanism which can be operated by the application of relatively small power by the operator and which 18 capable of exerting a relatively large force upon the mechanical memiber which is to be positioned.

A further object is -to produce such a mechanism adapted to position a member located at a considerable distance from the operator.

A fluid under pressure, such as steam, air, or water is used to exert force through the mechanism.

My improvement is illustrated herein as applied to a reverse lever of a steam-engine; but it is understood that the mechanism is applicable also for the positioning of other parts of a steam engine or parts of' other machinery or apparatus.

In the accompanying drawings, Figure 1 'is a side elevation of a mechanism embodying my improvement, a portion being in longitudinal upright section; Fig. 2 1s a section on the line, 2-2, of Fig. 1, looking toward the right; Fig. 3 is a section on the line, 33, of Fig. 1, looking toward the right; Fig. 4 is a section on the line, 1-4, of Fig. 1, looking toward the right; Fig. 5 is a section on the line, 55, of Fig. 1, lookview of a saddle plate; Fig. 7 is a section 7-7, of Fig. 1, looking toward the right;

Fig. 9 is a horizontal section on the line, 99, of Fig. 1.

Referring to said drawings, F is a reverse'arm rigid' on and rising from a horifrom one position to above Fig. 8 is a section on the line, 88, of Fig. 1, looking toward the right;

Patented J une 15, 1915.

nmifiemwn medseptember 26, @914. Serial-No. 863,743.

zontal rock shaft, F resting in a bearing, F. Said arm is the reverse arm of the revex-sing mechanism or of any steam engine having a reversing mechan sm. The work or function of my mechanism is the placing and holding of said arm in various chosen positions Within 1ts range of movement.

"G is -a quadrant lever hinged by its lower end at Q, to a relatively fixed portion of the locomotive and adapted to engage the quadrant, G, in different positions when said quadrant lever is by the operator changed another. Said lever may be any other form of hand lever.

Through a connection with the quadrant lever a portion of my positioning mechanism 1s so'adjusted as to permit the actuating fluid to so move other portions of the mechanism as to cause the reverse arm to change from one position to another corresponding to the change made by the quad rant lever. In such case, the arm of the operator exerts force upon the quadrant lever and through the latter upon a rela tively easily-movable member of my improved apparatus, and force is exerted upon the reverse lever by the pressure fluid and not by the arm of the operator, and the force exerted upon the reverse lever may be relatively large.

A cylinder, 0, is secured immovably to any relatively stationary portion of the locomotive, as, for example, the boiler. The cylinder has at one side and integral therewith upright portions, C adapted to bear against the boiler or other portion of the locomotive and be secured thereto by means of bolts, C

The upper portion of the cylinder rises the cylinder chamber and is made level to form a seat for a valve chest and a sliding valve member.

In the middle of such upper portion of the cylinder is an exhaust port, 0'', and rearward of said port, is an outer port, C, leading into the cylinder chamber at the rear end of the latter.

Forward of the middle port, C the cylinder has an outer part, C leading into the cylinder chamber at the forward end of the latter.

On the flat upper face of the cylinder rests the valve chest comprising the upright part, H, and the top plate, H

Bolts, H extend downward through the projecting edges of the top plate and are of a steam locomotive screw-threaded into the upper'portion f the cylinder. An inlet pipe, J, is applied to the top plate at the middle of the latter to transmit fluid under pressure through said plate into the space incloscd by said chest.

Within the chest, an inner valve member, 13, rests fiatwise upon the flat upper face of the-cylinder and is wide enough to fill the space between the side walls of the chest, but short enough to perm1t endwise sliding within the chest and upon the cylinder. Upon this valve member rests an outer valve member, G, shorter than the valve member,

.- B, but wide enough to fill the space between the side walls of the chest.

On the valve member, G, is a saddle plate, I, having at each end a downward BXlLl'lS1OI1, 1 extending over the upper port on of the adjacent end of the valve member, G. Said saddle plate is shown as Wide as the space between the side walls of the chest. In the upper portion of the member, G, is a cavity, 5, in which rests a spring, S bearing upward against the saddle plate, whereby the latter is pressed upward against the top plate, H of the chest, and the valve member, G, is pressed downward upon the valve niembemB, whereby the latter is pressed upon the flat upper face of the cyllnder.

A channel, 1 is formed in the upper face of the saddle plate along the middle longitudinal line of said plate. The inlet pipe, J, opens into said channel, so that the pressure fluid may pass from said pipe through said channel into both ends of the valve chest.

A. valve stem, G extends slidably through the rear wall of the chest and has its forward end joined to the outer valve member, G. The opposite or rear end of said stem is coupled at G to a link, G, which is also coupled. to the quadrant lever between the end of the latter. By shifting the quadrant lever forward or backward into various positions, the valve member. G, is moved in the same direction and through distances corresponding approximately to the distances through which the portion of the leing lever, D, the upper end of which is coupled at D to the lower end of the bracket,

D which is secured immovably to the boiler or any other portion of the locomotive (not The forward end of said l nk is coupled to the upright, oscillat-- shown). To give the lever, sufiicient length, it is extended across the piston stem,

P and the beam, E. The point at which the link, B is coupled to the lever, D, is

near the point, D ,-in order to give said lever a short arm and a long arm, the short arm acting on the link, B and imparting thereto a movement which is short relative tothe movement of the free end of the lever, so

that a relatively long movement of the piston stem, I, will produce a short movement of the link, B the valve stem, B and the inner valve, B, as hereinafterdescribed.

Within the cylinder is the piston head, P, and a piston stem, P extends horizontally through the forward end of the cylinder and a has its rear end secured to the piston head.

' A block, F, is rigidly secured to the forward end of the piston stem. A relatively stationary guide beam, E, is located below and parallel to the piston stem.

For the purpose of forming a connection between the piston stem and the free or swlnging end of the lever, D, a lateral extension is applied to the block, F, and ex tended downward below thebeam, E. For 7 forming said extension an upright bar, D", is placed at each side of the block, F, and secured thereto by means of bolts, f, and extended below the beam, 1*]. Y

Saddle blocks, D, are applied to the upper and lower edges of the beam, E, between the bars,- D. Bolts, 03, extend through said bars and saddle blocks and bind said members together. Said saddle blocks'are 'slidable on the beam, and said blocks and said bars, I), constitute a support and guide for the block, F, and the piston stem, P

and serve to compel the block, F, and the forward end of the parallel to said beam. 7

A horizontal link, D has its forward end extending between the lower ends of the bars, D, and is coupled thereto by a horizontal pin, D The rear end of said link, D is forked and extends to each side of the piston stem to travel lower end of the oscillating link, D, and is coupled theretoby a horizontal pin, D*.

At the middle of the inner valve member, B, is a middle exhaust port, 13, which extends through said member and stands above the cylinder port, C when the is in its middle position.

Rearward of the port, has an outer port, B which stands above the outer cylinder port, 0 when the valve,

B, is in its middle position.

Forward of the port, E the valve,=B, has another outer port, B*, which stands above the outer cylinder port, C, when said valve is in its middle. position.

The length'of the valve, G, is just suffi- B, the valve, B,

member, B,

cient to cover the ports, B and Beef the valve, B, when the valve, G, rests with its middle above the middle of the valve, B.

, verse lever, and the quadrant lever is then- In theilower face of the valve, .G, is a chamber or exhaust port, G which is so. located and of such length municate with t e exhaust ort, B9, of the valve, B. And said cham or or exhaust ort, G is of such length horizontally as to lieave a solid portion between said port and the end of the valve, G, sufiicient, and only suificient, to cover the adjacent port, B, or B, in-the valve, B, so that G, is in its middle osition upon the valve, B, the ports, B an E, are closed with the least possible lap? Under thls arrangement, a slight endwise movement of the valve, G, in either direction will correspondingly open the ports, B and B, one for taking the pressure fluid into the cylinder andthe other for exhausting the pressure fluid from the cylinder, the exhaust ports, (i B, and C being at all times 1n communication for the exhausting of fluid.

Assuming that the reverse leverand the quadrant are in their middle pos1t1ons and that the valve members, B and G, are in their middle positions, as shown in Fig. 1, so that the ports, B and B, are closed by the outer valve, G, and that it is desired to turn the reverse lever, F forward, then the quadrant lever, G, is moved forward so as move the link, G, forward as ,far as 1t is desired to move the upper end of the resecured in its new position on the quadrant. Such movement of the link, G correspondingly moves the stem, G and the outer valve, G, forward, whereby the port, B of the valve, B, is open to the valve chest and the port, B, is open to the exhaust port, G Thus pressure fluid is admltted into the portion of the cylinder at the rear of the piston head, P, and the latter and the piston stem, P, the block, F, and the'link,

. F and the'upper end of the. reverse lever,

F are driven forward. Such forward movement of the block, F, carries the bars,

D and the link, D and the lower end of the oscillating link, D, forward as far as the piston head is moved. Such movement of the link, D, draws the link, B the stem,

B and the valve, B, forward through adistance which is shorter than the distance throu h which the piston head travels. By such f brWard movement of the valve, B, the ports, B and B, move forward beneath the valve, G, until said ports are covered and closed by the valve, G. This cuts oii' both supply and exhaust of the pressure fluid, and the piston head is stopped and held. Reverse action takes place when the quadrant lever is mover rearward. Whenever the piston head is stopped, the piston stem, P the block, F, the link, F and the reverse arm, F are also stopped and held.

' The inner valve and the outer valve are connected independently of each other, the

as to at all times comwhen the valve,

of said former being moved only through the quad-- rant lever and the latter through the piston stem,

It is to be observed that if through leakage around the piston head or from any other cause there is accidental or abnormal movement of the piston head, the piston stem, P, the block, F, and the link, F, the valve, B, will be moved in the same direction and will open the ports, B and,B, to admit pressure fluid to the proper side of the piston head to return the latter to its proper position. Thus the position of the outer valve always determines the position of the piston head.

It is to be observed, also, that this, mecha-' nism is organized and arranged for precise movement and durability of the parts. The valves, B and G, are adapted to accurate travel, and the connections between the valve, G, and the quadrant lever and between the valve, B, and the block, -F, are adapted to produce tion and abnormal movement.

I claim as my invention,

In a mechanism of the nature described, a cylinder having a middle exhaust port and two outer ports, a piston head in said cylinder, a piston stem connected with said head and extending through one end of the cylinder, a member to be positioned, said member being in operative relation with said piston stem, a valve chest on said cylinder, two valve members within said chest and having ports and being slidable endwise independently of each other, a stem on each valve member independent of the other, a hand lever operatively connected with one stems, and means connected with the piston and with the other valve stem for the piston stem to said valve stem, substantially as described.

2. In a mechanism of the nature described, a cylinder having a middle exhaust port and two outer ports, a piston head in said cylinder, a piston stem connected with said head and extending through one end of the cylinder, a member to be positioned, said member being in operative relation with said piston stem, a valve chest on said cylinder, two valve members within said chest and having ports and being slidable endwise independently of each other, a stem on each valve member independent of andextending in the direction opposite the direction of the other, a hand lever operatively connected .with one of said stems, and means connected a minimum of lost mo-.

imparting a relatively slow movement from said cylinder, a piston stem connected "with said head and extendingthrough one end of the cylinder, a member to be positioned, said member being in operative relation with said piston stem, a valve chest on said cy1- inder, a saddle plate within said chest, two valve members within said chest and having ports and being slidable endwise independently of each other, a stem on each valve member independent of the other. a hand lever operatively connected with one of said stems, and means connected with the piston stem and with the other valve stem for imparting a relatively slow movement from the piston stem to said valve stem, substantially as described.

4;. In a mechanism of the nature de scribed, a cylinder having a middle exhaust port and two outer ports, a piston headin said cylinder, a piston stem connected with said head and extending through one end of the cylinder, a member to be positioned, said member being in operative relation with said piston stem, a valve" chest on said cylinder, a channeled saddle plate within said chest, two valve members within said chest and having ports and being slidable endwise independently of each other, a stem on each valve member independent of the other, a hand lever operatively connected with one of said stems, and means connected with the piston stem and with the other valve stem for imparting a relatively slow movement from the piston stem to said valve stem, substantially as described.

5. In a mechanism of the nature described, a cylinder having a middle exhaust port and two outer ports, a piston head in said cylinder, a piston stem connected with said head and extending through one end of the cylinder, a member to be positioned, said member being inoperative relation with said piston stem, a valve chest on said cylinder,'a saddle plate and a spring within said chest, two valve members within said chest and having ports and being slidable endwiseindependently of each other, a stem on each valve member independent of the other, a hand 1 lever operatively connected with one of said stems, and means connected with the piston stem and with the other valve stem for imparting a relatively slow movement from the piston stem to said valve stem, substantially as described.

6. In a mechanism of the nature described, a cylinder having a middle exhaust port and two outer ports, a piston head in said cylinder, a piston stem connected with said head and extending through'one end of the cylinder, a member extending laterally on the piston stem, a member to be positioned, said member being in operative relation with said piston stem, a valve chest on said cylinder; two valve members within i said chestand having ports and being slidable endwi'se independently of each other, a stem on each valve member'independent of the other, a hand lever operatively con.

nected with one of said stems, and means connected with the member extending laterally on the DIStOH stem and with the other valve stem for imparting a relatively slow 

